- Test inflated and rounded; tallest at apical disc; slight posterior heel; faint anterior sulcus.
- Apical disc ethmophract, 4 gonopores; all genital plates similar in size. Positioned close to the anterior.
- All ambulacra petaloid; more or less flush; open distally.
- Plastron plating not discernable on any specimen.
- Peristome small, circular to wekaly subpentagonal; very slightly depressed; situated about one-third test length from anterior; 2-3 phyllode pores in each ambulacrum surrounding peristome.
- Periproct supramarginal, on steeply sloping posterior face.
- Peripetalous fasciole passing several plates below the ends of the petals; passes beneath the ambitus around the anterior. No subanal fasciole.
- On aboral surface primary tubercles set in a dense matrix of granules.
||Upper Cretaceous (?Campanian), Guatamala.
||Barnumia browni Cooke, 1953, p. 29, by original designation. USNM 108407A.
||Only the type species.
|Classification and/or Status
Spatangoida, Hemiasterina, Aeropsidae.
A junior subjective synonym of Homoeaster Pomel, 1883.
||I have restudied the type. This closely resembles other species of Homoeaster in apical disc structure and fasciole development. It differs primarily in having ambulacra with more developed pore-pairs than in any other species.
Cooke, W. B. 1953. American Upper Cretaceous Echinoidea. Geological Survey Professional Paper 254-A, 1-44, pls 1-16.